Nitric Oxide Releasing Prodrugs of Diaryl-2-(5h)-Furanones as Cyclooxygenase-2 Inhibitors

ABSTRACT

The invention encompasses novel compounds of Formula I, which are nitric oxide-releasing prodrugs of diaryl-2-(5H) furanones useful in the treatment of cyclooxygenase-2 mediated diseases. 
     
       
         
         
             
             
         
       
     
     The invention also encompasses certain pharmaceutical compositions and methods for treating cyclooxygenase-2 mediated diseases comprising the use of compounds of Formula I. The above compounds may be used as a combination therapy with low-dose aspirin to treat chronic cyclooxygenase-2 mediated diseases or conditions while also reducing the risk of thrombotic cardiovascular events.

BACKGROUND OF THE INVENTION

Selective inhibitors of cyclooxygenase-2 are a sub-class of the class ofdrugs known as non-steroidal antiinflammatory drugs (NSAIDs). The NSAIDsare active in reducing the prostaglandin-induced pain and swellingassociated with the inflammation process but are also active inaffecting other prostaglandin-regulated processes not associated withthe inflammation process. Thus, use of high doses of most common NSAIDscan produce severe side effects, including life threatening ulcers, thatlimit their therapeutic potential. An alternative to NSAIDs is the useof corticosteroids, which have even more drastic side effects,especially when long term therapy is involved.

Previous NSAIDs have been found to prevent the production ofprostaglandin by inhibiting enzymes in the human arachidonicacid/prostaglandin pathway including the enzyme cyclooxygenase (COX).The discovery that there are two isoforms of the COX enzyme, the first,COX-1, being involved with physiological functions and the second,COX-2, being induced in inflamed tissue, has given rise to a newapproach. While conventional NSAIDs block both forms of the enzyme, theidentification of the inducible COX-2 enzyme associated withinflammation has provided a viable target of inhibition which moreeffectively reduces inflammation and produces fewer and less drasticside effects. Many compounds which have activity as COX-2 inhibitorshave been identified, including rofecoxib (VIOXX®), etoricoxib(ARCOXMA™), celecoxib (CELEBREX®) and valdecoxib (BEXTRA™), and muchresearch continues in this area.

Many patients suffering from a chronic cyclooxygenase-2 mediated diseaseor condition are elderly and thus are at increased risk for thromboticcardiovascular events, such as stroke, myocardial ischemia, myocardialinfarction, angina pectoris, transient ischemic attack (TIA; amaurosisfugax), reversible ischemic neurologic deficits, and any similarthrombotic event in any vascular bed (splanchnic, renal, aortic,peripheral, etc.). Moreover, there is evidence that patients withchronic inflammatory conditions, such as rheumatoid arthritis andsystemic lupus erythematosis are at increased risk for thromboticcardiovascular events. It is desirable that such patients receiveappropriate therapy to reduce their risk of such events, such aslow-dose aspirin therapy. However, it has been reported that theco-administration of aspirin and a selective COX-2 inhibitor in a ratmodel resulted in substantially more severe gastric injury than isproduced with either agent alone. See Fiorucci et al., Gastroenterology,vol. 123, pp. 1598-1606, 2002. Thus, the major advantage that COX-2selective inhibitors have over NSAIDS may be offset by the concomitantuse of aspirin.

NO-releasing forms of non-steroidal anti-inflammatory drugs are known inthe art and are reported to have improved gastrointestinal andcardiovascular safety profiles over their conventional NSAIDcounterparts. Furthermore, NO-releasing forms of selectivecyclooxygenase-2 selective inhibitors are disclosed in WO 01/45703,published on Jun. 28, 2001.

The present invention provides for novel nitrosated prodrugs forcyclooxygenase-2 selective inhibitors that are useful for treatingcyclooxygenase-2 mediated diseases or conditions and can be administeredalone or in combination with low-dose aspirin. The invention providesefficacy in treating chronic cyclooxygenase-2 mediated diseases orconditions, effectively reduces the risk of thrombotic cardiovascularevents and potentially renal side effects and at the same time reducesthe risk of GI ulceration or bleeding.

SUMMARY OF THE INVENTION

The invention encompasses novel compounds of Formula I, which are nitricoxide-releasing prodrugs of diaryl-2-(5H) furanones useful in thetreatment of cyclooxygenase-2 mediated diseases:

The invention also encompasses certain pharmaceutical compositions andmethods for treating cyclooxygenase-2 mediated diseases comprising theuse of compounds of Formula I. The above compounds may be used as acombination therapy with low-dose aspirin to treat chroniccyclooxygenase-2 mediated diseases or conditions while also reducing therisk of thrombotic cardiovascular events.

DETAILED DESCRIPTION OF THE INVENTION

The invention encompasses novel compounds of Formula I as prodrugs thatconvert in vivo to diaryl-2-(5H)-furanones and useful in the treatmentof cyclooxygenase-2 mediated diseases:

or a pharmaceutically acceptable salt thereof, wherein:n is an integer from 1 to 6;R¹ is selected from the group consisting of:

(a) S(O)₂CH₃ and

(b) S(O)₂NH₂,

R² and R³ each are independently selected from the group consisting of:

(a) hydrogen,

(b) halo,

(c) C₁₋₆alkoxy,

(d) C₁₋₆alkylthio,

(e) CN,

(f) CF₃,

(g) C₁₋₆alkyl, and

(h) N₃;

R⁴ is selected from the group consisting of

-   -   (a) C₁₋₄alkyl, optionally substituted with 1 to 3 halo groups,    -   (b) phenyl, naphthyl or a 5- or 6-membered aromatic heterocycle,        each optionally substituted with 1 to 3 halo groups,    -   (c) —O—R⁵, and    -   (b) —(CH₂)_(m)—N(R⁶)(R⁷);        m is an integer from 1 to 4; and        R⁵, R⁶ and R⁷ are each independently selected from the group        consisting of hydrogen and C₁₋₄alkyl, optionally substituted        with 1 to 3 halo groups.

A embodiment of the invention encompasses a compound of Formula Iwherein R¹ is S(O)₂CH₃, and R² and R³ are both hydrogen.

Another embodiment of the invention encompasses a compound of Formula Iwherein n is 1, 2 or 3.

Another embodiment of the invention encompasses a compound of Formula Iwherein R⁴ is C₁₋₄alkyl.

Another embodiment of the invention encompasses a compound of Formula Iwherein R⁴ is methyl.

The invention also encompasses a pharmaceutical composition comprising acompound of Formula I and a pharmaceutically acceptable carrier.

The invention also encompasses a method of treating an inflammatorydisease susceptible to treatment with a non-steroidal anti-inflammatoryagent comprising administering to a patient in need of such treatment ofa non-toxic therapeutically effective amount of a compound of Formula I.Within this embodiment is encompassed the above method wherein thepatient is also at risk of a thrombotic cardiovascular event and thepatient is on aspirin therapy to reduce the risk of the cardiovascularevent.

Another embodiment of the invention encompasses a method of treatingcyclooxygenase mediated diseases advantageously treated by an activeagent that selectively inhibits COX-2 in preference to COX-1 comprisingadministering to a patient in need of such treatment of a non-toxictherapeutically effective amount of a compound of Formula I. Within thisembodiment is encompassed the above method wherein the patient is alsoat risk of a thrombotic cardiovascular event and the patient is onaspirin therapy to reduce the risk of the cardiovascular event.

Another embodiment of the invention encompasses a method for treating achronic cyclooxygenase-2 mediated disease or condition and reducing therisk of a thrombotic cardiovascular event in a human patient in need ofsuch treatment and at risk of a thrombotic cardiovascular eventcomprising orally concomitantly or sequentially administering to saidpatient a compound of Formula I in an amount effective to treat thecyclooxygenase-2 mediated disease or condition and aspirin in an amounteffective to reduce the risk of the thrombotic cardiovascular event.Within this embodiment is encompassed the above method wherein thecompound of Formula I is administered orally on a once daily basis.Within this embodiment is encompassed the above method wherein thecompound of Formula I is administered orally on a twice daily basis.Within this embodiment is encompassed the above method wherein thecyclooxygenase-2 selective mediated disease or condition is selectedfrom the group consisting of: osteoarthritis, rheumatoid arthritis andchronic pain. Within this embodiment is encompassed the above methodwherein aspirin is administered at a dose of about 30 mg to about 1 g.Within this embodiment is encompassed the above method wherein aspirinis administered at a dose of about 80 to about 650 mg. Within thisembodiment is encompassed the above method wherein aspirin isadministered at a dose of about 81 mg or about 325 mg. Within thisembodiment is encompassed the above method wherein aspirin is orallyadministered once daily.

The invention also encompasses a pharmaceutical composition comprising acompound of Formula I and aspirin in combination with a pharmaceuticallyacceptable carrier.

The term “halogen” or “halo” includes F, Cl, Br, and I.

The term “alkyl” means linear or branched structures and combinationsthereof, having the indicated number of carbon atoms. Thus, for example,C₁₋₆alkyl includes methyl, ethyl, propyl, 2-propyl, s- and t-butyl,butyl, pentyl, hexyl, 1,1-dimethylethyl, cyclopropyl, cyclobutyl,cyclopentyl and cyclohexyl.

The term “alkoxy” means alkoxy groups of a straight or branchedconfiguration having the indicated number of carbon atoms. C₁₋₆alkoxy,for example, includes methoxy, ethoxy, propoxy, isopropoxy, and thelike.

The term “alkylthio” means alkylthio groups having the indicated numberof carbon atoms of a straight or branched configuration. C₁₋₆alkylthio,for example, includes methylthio, propylthio, isopropylthio, and thelike.

The term “5- or 6-membered aromatic heterocycle” means for example,pyrrole, furan, thiophene, imidazole, pyrazole, oxazole, isoxazole,thiazole, isothiazole, triazole, oxadiazole, thiadiazole, tetrazole,pyridine, pyridine, pyrazine, pyridazine and triazine.

Some of the compounds described herein contain olefinic double bonds,and unless specified otherwise, are meant to include both E and Zgeometric isomers. Compounds of Formula I may contain one or moreasymmetric centers and can thus occur as racemates and racemic mixtures,single enantiomers, diastereomeric mixtures and individualdiastereomers. The present invention is meant to comprehend all suchisomeric forms of the compounds of Formula I.

The term “treating a chronic cylcooxygenase-2 mediated disease orcondition” means treating or preventing any chronic disease or conditionthat is advantageously treated or prevented by inhibiting thecyclooxygenase-2 enzyme. The term includes the relief of pain, fever andinflammation of a variety of conditions including rheumatic fever,symptoms associated with influenza or other viral infections, commoncold, low back and neck pain, dysmenorrhea, headache, migraine (acuteand prophylactice treatment), toothache, sprains and strains, myositis,neuralgia, synovitis, arthritis, including rheumatoid arthritis,degenerative joint diseases (osteoarthritis), gout and ankylosingspondylitis, acute, subacute and chronic musculoskeletal pain syndromessuch as bursitis, burns, injuries, and pain following surgical anddental procedures as well as the preemptive treatment of surgical pain.In addition, the term includes the inhibition cellular neoplastictransformations and metastic tumor growth and hence the treatment ofcancer. The term also includes the treatment of endometriosis andParkinson's disease as well as the treatment of cyclooxygenase-mediatedproliferative disorders such as may occur in diabetic retinopathy andtumor angiogenesis. The term “treating” encompasses not only treating apatient to relieve the patient of the signs and symptoms of the diseaseor condition but also prophylactically treating an asymptomatic patientto prevent the onset or progression of the disease or condition.

A “thrombotic cardiovascular event” is defined as any sudden event of atype known to be caused by platelet aggregation, thrombosis, andsubsequent ischemic clinical events, including thrombotic orthromboembolic stroke, myocardial ischemia, myocardial infarction,angina pectoris, transient ischemic attack (TIA; amaurosis fugax),reversible ischemic neurologic deficits, and any similar thromboticevent in any vascular bed (splanchnic, renal, aortic, peripheral, etc.).

The term “patient in need of such treatment and at risk of a thromboticcardiovascular event” means a patient in need of both treatment for acyclooxygenase-2 mediated disease and also at risk of a thromboticcardiovascular event. One skilled in the art can diagnose a patient thatis in need of treatment for a cyclooxygenase-2 mediated disease orcondition and also at risk of suffering a thrombotic cardiovascularevent. For example, such a patient may be over the age of 50 withosteoarthritis and with a previous myocardial infarction. Other riskfactors for a thrombotic cardiovascular event include hypertension,hypercholesterolemia; diabetes mellitus, chronic renal impairment,smoking, and any prior personal or family history of such an event.Administration of the drug combination to the patient includes bothself-administration and administration to the patient by another person.

The term “amounts that are effective to treat” is intended to mean thatamount of a drug or pharmaceutical agent that will elicit the biologicalor medical response of a tissue, a system, animal or human that is beingsought by a researcher, veterinarian, medical doctor or other clinician.The term also encompasses the amount of a pharmaceutical drug that willprevent or reduce the risk of occurrence of the biological or medicalevent that is sought to be prevented in a tissue, a system, animal orhuman by a researcher, veterinarian, medical doctor or other clinician.The inhibitor of cyclooxygenase-2 may be administered at a dosage levelup to conventional dosage levels for NSAIDs. Suitable dosage levels ofthe compound of Formula I used in the present invention are describedbelow. The compound may be administered on a regimen of once or twiceper day.

The term “amount effective to reduce the risk of” means the amount of apharmaceutical drug that will prevent or reduce the risk of occurrenceof the biological or medical event that is sought to be prevented in atissue, a system, animal or human by a researcher, veterinarian, medicaldoctor or other clinician. Aspirin is administered at a dose of about 30mg to about 1 g once daily, preferably at a dose of about 80 mg to about650 mg.

The term “concomitantly administering” means administering the agentssubstantially concurrently. The term “concomitantly administering”encompasses not only administering the two agents in a singlepharmaceutical dosage form but also the administration of each activeagent in its own separate pharmaceutical dosage formulation. Whereseparate dosage formulations are used, the agents can be administered atessentially the same time, i.e., concurrently.

The term “sequentially administering” means administering the agents atseparately staggered times. Thus, agents can be sequentiallyadministered such that the beneficial pharmaceutical effect of aspirinand a compound of the present invention are realized by the patient atsubstantially the same time. Thus, for example, if a compound of thepresent invention and aspirin are both administered on a once a daybasis, the interval of separation between sequential administration ofthe two agents can be up to twelve hours apart.

The pharmaceutical compositions of the present invention comprise acompound of Formula I as an active ingredient or a pharmaceuticallyacceptable salt, thereof, and may also contain a pharmaceuticallyacceptable carrier and optionally other therapeutic ingredients. Theterm “pharmaceutically acceptable salts” include salts prepared frombases that result in non-toxic pharmaceutically acceptable salts,including inorganic bases and organic bases. Salts derived frominorganic bases include aluminum, ammonium, calcium, copper, ferric,ferrous, lithium, magnesium, manganic salts, manganous, potassium,sodium, zinc, and the like. Particularly preferred are the ammonium,calcium, magnesium, potassium, and sodium salts. Salts derived frompharmaceutically acceptable organic non-toxic bases include salts ofprimary, secondary, and tertiary amines, substituted amines includingnaturally occurring substituted amines, cyclic amines, and basic ionexchange resins, such as arginine, betaine, caffeine, choline,N,N-dibenzylethylenediamine, diethylamine, 2-diethylaminoethanol,2-dimethylaminoethanol, ethanolamine, ethylenediamine,N-ethylmorpholine, N-ethylpiperidine, glucamine, glucosamine, histidine,hydrabamine, isopropylamine, lysine, methylglucamine, morpholine,piperazine, piperidine, polyamine resins, procaine, purines,theobromine, triethylamine, trimethylamine, tripropylamine,tromethamine, and the like.

When the compound of the present invention is basic, salts may beprepared from acids that result in pharmaceutically acceptable salts,including inorganic and organic acids. Such acids include acetic,adipic, aspartic, 1,5-naphthalenedisulfonic, benzenesulfonic, benzoic,camphorsulfonic, citric, 1,2-ethanedisulfonic, ethanesulfonic,ethylenediaminetetraacetic, fumaric, glucoheptonic, gluconic, glutamic,hydriodic, hydrobromic, hydrochloric, isethionic, lactic, maleic, malic,mandelic, methanesulfonic, mucic, 2-naphthalenesulfonic, nitric, oxalic,pamoic, pantothenic, phosphoric, pivalic, propionic, salicylic, stearic,succinic, sulfuric, tartaric, p-toluenesulfonic acid, undecanoic,10-undecenoic, and the like.

The compounds of Formula I are prodrugs of cyclooxygenase-2 selectiveinhibitors which covert in vivo to diaryl-2-(5H)-furanones. Thecompounds also liberate nitric oxide in vivo, which is believed tocontribute to an improved gastrointestinal and potentially renal safetyprofile. As such, the compounds of the present invention may be co-dosedwith low-dose aspirin to treat chronic cyclooxygenase-2 mediateddiseases or conditions, effectively reduce the risk of thromboticcardiovascular events and potentially renal side effects and at the sametime reduce the risk of GI ulceration or bleeding. Thus, patients withhypertension and cardiovascular disease, as well as potentially patientswith renal insufficiency, would actively benefit from being administeredcompounds of the present invention over NSAIDs and cyclooxygenase-2selective inhibitors currently available.

By virtue of the cyclooxygenase-2 activity of the active moiety of theprodrugs of the present invention, the compounds of Formula I aretherefore useful for the relief of pain, fever and inflammation of avariety of conditions including rheumatic fever, symptoms associatedwith influenza or other viral infections, common cold, low back and neckpain, dysmenorrhea, headache, migraine (acute and prophylacticstreatment), toothache, sprains and strains, myositis, neuralgia,synovitis, arthritis, including rheumatoid arthritis, degenerative jointdiseases (osteoarthritis), gout and ankylosing spondylitis, acute,subacute and chronic musculoskeletal pain syndromes such as bursitis,burns, injuries, and pain following surgical and dental procedures aswell as the preemptive treatment of surgical pain. In addition, such acompound may inhibit cellular neoplastic transformations and metastictumor growth and hence can be used in the treatment of cancer. Compoundsof Formula I may also be useful for the treatment or prevention ofendometriosis, and Parkinson's disease.

Compounds of Formula I will also inhibit prostanoid-induced smoothmuscle contraction by preventing the synthesis of contractileprostanoids and hence may be of use in the treatment of dysmenorrhea,premature labor and asthma.

By virtue of the high cyclooxygenase-2 (COX-2) activity and/or theselectivity for cyclooxygenase-2 over cyclooxygenase-1 (COX-1) of theactive moiety of the prodrugs of the invention as defined above,compounds of Formula I will prove useful as an alternative toconventional non-steroidal antiinflammatory drugs (NSAID'S) particularlywhere such non-steroidal antiinflammatory drugs may be contra-indicatedsuch as in patients with peptic ulcers, gastritis, regional enteritis,ulcerative colitis, diverticulitis or with a recurrent-history ofgastrointestinal lesions; GI bleeding, coagulation disorders includinganemia such as hypoprothrombinemia, haemophilia or other bleedingproblems (including those relating to reduced or impaired plateletfunction); kidney disease (e.g. impaired renal function); those prior tosurgery or taking anticoagulants; and those susceptible to NSAID inducedasthma.

Similarly, compounds of Formula I will be useful as a partial orcomplete substitute for conventional NSAIDs in preparations wherein theyare presently co-administered with other agents or ingredients. Thus infurther aspects, the invention encompasses pharmaceutical compositionsfor treating cyclooxygenase-2 mediated diseases as defined abovecomprising a non-toxic therapeutically effective amount of the compoundof Formula I as defined above and one or more ingredients such asanother pain reliever including acetominophen or phenacetin; opioidanalgesics, such as codeine, fentanyl, hydromorphone, levorphanol,meperidine, methadone, morphine, oxycodone, oxymorphine, propoxyphene,buprenorphine, butorphanol, dezocine, nalbuphine and pentazocine; apotentiator including caffeine; an H2-antagonist; aluminum or magnesiumhydroxide; simethicone; a decongestant including phenylephrine,phenylpropanolamine, pseudophedrine, oxymetazoline, ephinephrine,naphazoline, xylometazoline, propylhexedrine, or levo-desoxyephedrine;an antitussive including codeine, hydrocodone, caramiphen,carbetapentane, or dextramethorphan; a diuretic; a sedating ornon-sedating antihistamine; and a proton pump inhibitor, such asomeprazole. For the treatment or prevention of migraine, the inventionalso encompasses co-administration with a 5-HT agonist such asrizatriptan, sumatriptan, zolmitriptan and naratriptan. In addition theinvention encompasses a method of treating cyclooxygenase mediateddiseases comprising: administration to a patient in need of suchtreatment a non-toxic therapeutically effect amount of the compound ofFormula I, optionally co-administered with one or more of suchingredients as listed immediately above.

Compounds of the present invention are prodrugs of inhibitors ofcyclooxygenase-2 and are thereby useful in the treatment ofcyclooxygenase-2 mediated diseases as enumerated above. This activity isillustrated by their ability to selectively inhibit cyclooxygenase-2over cyclooxygenase-1. Accordingly, the ability of the compounds of thisinvention to convert to the active compound and thus treatcyclooxygenase mediated diseases can be demonstrated by measuring theamount of prostaglandin E₂ (PGE₂) synthesized in the presence ofarachidonic acid, cyclooxygenase-1 or cyclooxygenase-2 and a compound ofFormula I as illustrated in the assays that follow. The IC₅₀ valuesrepresent the concentration of inhibitor required to return PGE₂synthesis to 50% of that obtained as compared to the uninhibitedcontrol. For the treatment of any of these cyclooxygenase mediateddiseases, compounds of Formula I may be administered orally, topically,parenterally, by inhalation spray or rectally in dosage unitformulations containing conventional non-toxic pharmaceuticallyacceptable carriers, adjuvants and vehicles. Compounds of the inventionmay be administered via the buccal or sublingual mucosa in the oralcavity. The term parenteral as used herein includes subcutaneousinjections, intravenous, intramuscular, intrasternal injection orinfusion techniques. Compounds of the invention may also be administeredthrough the nasal, pulmonary (inhalation aerosol) or ocular route. Inaddition to the treatment of warm-blooded animals such as mice, rats,horses, cattle, sheep, dogs, cats, etc., the compound of the inventionis effective in the treatment of humans.

As indicated above, pharmaceutical compositions for treatingcyclooxygenase-2 mediated diseases as defined may optionally include oneor more ingredients as listed above.

The pharmaceutical compositions containing the active ingredient may bein a form suitable for oral use, for example, as tablets, troches,lozenges, aqueous or oily suspensions, dispersible powders or granules,emulsions, hard or soft capsules, or syrups or elixirs. Compositionsintended for oral use may be prepared according to any method known tothe art for the manufacture of pharmaceutical compositions and suchcompositions may contain one or more agents selected from the groupconsisting of sweetening agents, flavoring agents, coloring agents andpreserving agents in order to provide pharmaceutically elegant andpalatable preparations. Tablets contain the active ingredient inadmixture with non-toxic pharmaceutically acceptable excipients whichare suitable for the manufacture of tablets. These excipients may be forexample, inert diluents, such as calcium carbonate, sodium carbonate,lactose, calcium phosphate or sodium phosphate; granulating anddisintegrating agents, for example, corn starch, or alginic acid;binding agents, for example starch, gelatin or acacia, and lubricatingagents, for example, magnesium stearate, stearic acid or talc. Thetablets may be uncoated or they may be coated by known techniques todelay disintegration and absorption in the gastrointestinal tract andthereby provide a sustained action over a longer period. For example, atime delay material such as glyceryl monostearate or glyceryl distearatemay be employed. They may also be coated by the technique described inthe U.S. Pat. Nos. 4,256,108; 4,166,452; and 4,265,874 to form osmotictherapeutic tablets for control release.

Formulations for oral use may also be presented as hard gelatin capsuleswherein the active ingredient is mixed with an inert solid diluent, forexample, calcium carbonate, calcium phosphate or kaolin, or as softgelatin capsules wherein the active ingredients is mixed with water oran oil medium, for example peanut oil, liquid paraffin, or olive oil.

Aqueous suspensions contain the active material in admixture withexcipients suitable for the manufacture of aqueous suspensions. Suchexcipients are suspending agents, for example sodiumcarboxymethyl-cellulose, methyl cellulose,hydroxypropylmethyl-cellulose, sodium alginate, polyvinyl-pyrrolidone,gum tragacanth and gum acacia; dispersing or wetting agents may be anaturally-occurring phosphatide, for example lecithin, or condensationproducts of an alkylene oxide with fatty acids, for examplepolyoxyethylene stearate, or condensation products of ethylene oxidewith long chain aliphatic alcohols, for exampleheptadecaethylene-oxycetanol, or condensation products of ethylene oxidewith partial esters derived from fatty acids and a hexitol such aspolyoxyethylene sorbitol monooleate, or condensation products ofethylene oxide with partial esters derived from fatty acids and hexitolanhydrides, for example polyethylene sorbitan monooleate. The aqueoussuspensions may also contain one or more preservatives, for exampleethyl, or n-propyl, p-hydroxybenzoate, one or more coloring agents, oneor more flavoring agents, and one or more sweetening agents, such assucrose, saccharin or aspartame.

Liquid formulations include the use of self-emulsifying drug deliverysystems and NanoCrystal® technology. Cyclodextrin inclusion complexescan also be utilized.

Oily suspensions may be formulated by suspending the active ingredientin a vegetable oil, for example arachis oil, olive oil, sesame oil orcoconut oil, or in mineral oil such as liquid paraffin. The oilysuspensions may contain a thickening agent, for example beeswax, hardparaffin or cetyl alcohol. Sweetening agents such as those set forthabove, and flavoring agents may be added to provide a palatable oralpreparation. These compositions may be preserved by the addition of ananti-oxidant such as ascorbic acid.

Dispersible powders and granules suitable for preparation of an aqueoussuspension by the addition of water provide the active ingredient inadmixture with a dispersing or wetting agent, suspending agent and oneor more preservatives. Suitable dispersing or wetting agents andsuspending agents are exemplified by those already mentioned above.Additional excipients, for example sweetening, flavoring and coloringagents, may also be present.

The pharmaceutical compositions of the invention may also be in the formof an oil-in-water emulsions. The oily phase may be a vegetable oil, forexample olive oil or arachis oil, or a mineral oil, for example liquidparaffin or mixtures of these. Suitable emulsifying agents may benaturally-occurring phosphatides, for example soy bean, lecithin, andesters or partial esters derived from fatty acids and hexitolanhydrides, for example sorbitan monooleate, and condensation productsof the said partial esters with ethylene oxide, for examplepolyoxyethylene sorbitan monooleate. The emulsions may also containsweetening and flavouring agents.

Syrups and elixirs may be formulated with sweetening agents, for exampleglycerol, propylene glycol, sorbitol or sucrose. Such formulations mayalso contain a demulcent, a preservative and flavoring and coloringagents. The pharmaceutical compositions may be in the form of a sterileinjectable aqueous or oleagenous suspension. This suspension may beformulated according to the known art using those suitable dispersing orwetting agents and suspending agents which have been mentioned above.The sterile injectable preparation may also be a sterile injectablesolution or suspension in a non-toxic parenterally-acceptable diluent orsolvent, for example as a solution in 1,3-butane diol. Among theacceptable vehicles and solvents that may be employed are water,Ringer's solution and isotonic sodium chloride solution. In addition,sterile, fixed oils are conventionally employed as a solvent orsuspending medium. For this purpose any bland fixed oil may be employedincluding synthetic mono- or diglycerides. In addition, fatty acids suchas oleic acid find use in the preparation of injectables.

Compounds of Formula I may also be administered in the form ofsuppositories for rectal administration of the drug. These compositionscan be prepared by mixing the drug with a suitable non-irritatingexcipient which is solid at ordinary temperatures but liquid at therectal temperature and will therefore melt in the rectum to release thedrug. Such materials are cocoa butter and polyethylene glycols.

For topical use, creams, ointments, jellies, solutions or suspensions,etc., containing the compound of Formula I are employed. (For purposesof this application, topical application shall include mouth washes andgargles.)

Pharmaceutical compositions of the invention may also utilize absorptionenhancers such as tween 80, tween 20, Vitamin E TPGS (d-alpha-tocopherylpolyethylene glycol 1000 succinate) and Gelucire®.

Dosage levels of the order of from about 0.01 mg to about 140 mg/kg ofbody weight per day are useful in the treatment of the above-indicatedconditions, or alternatively about 0.5 mg to about 7 g per patient perday. For example, inflammation may be effectively treated by theadministration of from about 0.01 to 50 mg of the compound per kilogramof body weight per day, or alternatively about 0.5 mg to about 3.5 g perpatient per day, preferably 2.5 mg to 1 g per patient per day.

The amount of active ingredient that may be combined with the carriermaterials to produce a single dosage form will vary depending upon thehost treated and the particular mode of administration. For example, aformulation intended for the oral administration of humans may containfrom 0.5 mg to 5 g of active agent compounded with an appropriate andconvenient amount of carrier material which may vary from about 5 toabout 95 percent of the total composition. Dosage unit forms willgenerally contain between from about 1 mg to about 500 mg of an activeingredient, typically 25 mg, 50 mg, 100 mg, 200 mg, 300 mg, 400 mg, 500mg, 600 mg, 800 mg, or 1000 mg.

It will be understood, however, that the specific dose level for anyparticular patient will depend upon a variety of factors including theage, body weight, general health, sex, diet, time of administration,route of administration, rate of excretion, drug combination and theseverity of the particular disease undergoing therapy.

Methods of Synthesis

Stilbene derivatives useful as cyclooxygenase-2 selective inhibitors aredisclosed in U.S. Pat. No. 5,849,943, which is hereby incorporate byreference in its entirety.

Diaryl-2-(5H)-furanones useful as COX-2 inhibitors are known in the artand disclosed in U.S. Pat. No. 5,474,995, which is hereby incorporatedby reference in its entirety. Methods for making diaryl-2-(5H)-furanonesuseful as COX-2 inhibitors are disclosed in U.S. Pat. No. 5,840,924,which is hereby incorporated by reference in its entirety. Rofecoxib,sold under the tradename VIOXX, is known in the art and commerciallyavailable.

Compounds of the invention can be synthesized according to the followingsynthetic scheme:

Abbreviations used in Scheme 1D.M.=Dess-Martin reagentHF.pyr=hydrogen fluoride pyridine (70/30)

Assays for Determining Biological Activity

The compound of Formula I can be tested using the following assays todetermine their biological activity.

Inhibition of Cyclooxygenase Activity

Compounds are tested as inhibitors of cyclooxygenase activity in wholecell and microsomal cyclooxygenase assays. Both of these assays measureprostaglandin E₂ (PGE₂) synthesis in response to arachidonic acid, usinga radioimmunoassay. Cells used for whole cell assays, and from whichmicrosomes are prepared for microsomal assays, are human osteosarcoma143 cells (which specifically express cyclooxygenase-2) and human U-937cells (which specifically express cyclooxygenase-1). In these assays,100% activity is defined as the difference between prostaglandin E₂synthesis in the absence and presence of arachidonate addition. IC₅₀values represent the concentration of putative inhibitor required toreturn PGE₂ synthesis to 50% of that obtained as compared to theuninhibited control.

A. Microsomal Cyclooxygenase Assay

Cox microsomal fractions are prepared as previously described (Percivalet al., Arch. Biochem. Biophys. (1994) 315:111-118). The enzymereactions are performed in 50 mM KPi pH 8.0, 1 μM heme, 1 mM phenolsupplemented with 10 μg/ml of each Cox-1 or Cox-2 microsomal fractions.1 μl DMSO or test compound (100 fold stock concentrated in DMSO) areadded to 100 μl buffer. The enzyme reaction is initiated 15 minuteslater by the addition of 10 μl of 100 μM arachidonic acid. The enzymereaction is allowed to proceed for 5 minutes at room temperature beforebeing stopped by the addition of 10 μl 1 N HCl. PGE₂ levels are thendetermined by EIA (Assay Designs) using the manufacturer's instruction.

This assay may be used to demonstrate that the unconverted prodrugs ofthe instant invention are inactive against both COX-1 and COX-2.

B. Human Whole Blood Cyclooxygenase Assay Rationale

Whole blood provides a protein and cell-rich milieu for the study ofbiochemical efficacy of anti-inflammatory compounds such as COX-2inhibitors and NSAIDs. To study the inhibitory activities of thesecompounds on the two isoforms of cyclooxygenase (COX-1 and COX-2), humanblood is either stimulated with lipopolysaccharide (LPS) for 24 hours toinduce COX-2 or the blood is allowed to clot spontaneously to activateCOX-1. The production of prostaglandin E₂ (PGE₂) and thromboxane B₂(TXB₂) are measured by immunoassay at the end of the incubation asreadouts of COX-2 and COX-1 activity, respectively.

Methods

Human whole blood assays for COX-1 and COX-2 activity, previouslyreported (Brideau et al, 1996) are performed as described below.

1. COX-2 (LPS-Induced PGE₂ Production):

Fresh blood is collected in heparinized tubes by venipuncture fromhealthy male volunteers. These subjects have no apparent inflammatoryconditions and have not taken any NSAIDs for at least 7 days prior toblood collection. The blood is initially pre-incubated with bacteriallipopolysaccharide (LPS) at 100 g/1 ml (Sigma Chem, #L-2630 from E.coli, serotype 0111:B4; diluted in 0.1% w/v bovine serine albumin inphosphate buffered saline). Five minutes later, 500 μL aliquots of theLPS-treated blood aree incubated with 2 μL vehicle (DMSO) or 2 μL oftest compounds in DMSO for 24 hr at 37° C. (for induction of COX-2).Unstimulated control blood at time zero (no LPS) is used as blank. Atthe end of the 24 hr incubation, the blood is centrifuged at 3,000 rpmsfor 10 min at 40° C. to obtain plasma. The plasma is assayed for PGE₂using an enzyme immunoassay kit (Assay Designs, 901-001) according tothe manufacturer's instructions.

2. COX-1 (Clotting-Induced TXB2 Production):

Fresh blood from male or female volunteers is collected into vacutainerscontaining no anticoagulants. These subjects have no apparentinflammatory conditions and have not taken any NSAIDs for at least 7days prior to blood collection. Aliquots of 500 L are immediatelytransferred to polypropylene tubes preloaded with 2 μL of DMSO or 2 μLof test compounds. The tubes are vortexed and incubated at 37° C. for 1h to allow the blood to clot. At the end of the incubation, serum isobtained by centrifugation (3,000 rpm for 10 min at 40° C.). The serumis obtained and is assayed for TXB₂ using an enzyme immunoassay kit(Assay Designs, 901-002) according to the manufacturer's instructions.

Representative Rat Paw Edema Assay—Protocol Rationale

The carrageenan-induced rat paw edema assay is an established assay forevaluating the efficacy of conventional, non-selective NSAIDs in acuteinflammation (Winter and Flataker, 1965; Mukheijee et al., 1996; Vinegaret al., 1987).

Methods

Male Sprague-Dawley rats (200-250 g) are fasted for 16-18 h prior tooral administration of either the vehicle (0.5% methocel) or testcompound. One hour later, a line was drawn using a permanent marker at alevel above the ankle in one hind paw to define the area of the paw tobe monitored. The paw volume (V₀) is measured using a plethysmometer(Ugo-Basile, Italy) based on the Archimedes principle of waterdisplacement. The rats are then injected subplantarly with 0.05 mL of a1% carrageenan (Sigma Chem.) solution in saline using a syringe with a27-gauge needle (i.e. 500 μg carrageenan per paw). Three hours later,the paw volume (V₃) is measured again and the increases in paw volume(V₃-V₀) is calculated. Paw edema is compared with the vehicle-controlgroup and the percent inhibition calculated taking the values in thecontrol group as 0%.

NSAID-Induced Gastropathy in Rats Rationale

The major side effect of conventional NSAIDs is their ability to producegastric lesions in man. Rats are sensitive to the actions of NSAIDs andhave been used commonly in the past to evaluate the gastrointestinalside effects of current conventional NSAIDs. In the present assay,NSAID-induced gastrointestinal damage is observed by measuring urinary⁵¹Cr excretion after oral dosing of 5¹Cr-EDTA. Urinary 5¹Cr excretion isa well-established and sensitive technique to detect gastrointestinalintegrity in animals and man.

Methods

Male Sprague-Dawley rats (150-200 g) are administered orally a testcompound either once (acute dosing) or in multiple doses for a few days(chronic dosing). Immediately after the administration of the last dose,the rats are given an oral dose of ⁵¹Cr-EDTA (10 μCi/rat). The animalsare placed individually in metabolism cages with food and water ad lib.Urine is collected for a 24 hr period and ⁵¹Cr urinary excretion iscalculated as a percent of total ingested dose.

Protein-Losing Gastrophathy in Squirrel Monkeys Rationale

Protein-losing gastropathy (manifested as appearance of circulatingcells and plasma proteins in the GI tract) is a significant anddose-limiting adverse response to NSAIDs. This can be quantitativelyassessed by intravenous administration or ⁵¹CrCl₃ solution. Thisisotopic ion can avidly bind to cell and serum globins and cellendoplasmic reticulum. Measurement of radioactivity appearing in fecescollected for 24 hr after administration of the isotope thus provides asensitive and quantitative index of protein-losing gastropathy.

Methods

Groups of male squirrel monkeys (0.8 to 1.4 kg) are treated by gavagewith 1% methocel

or a test compounds at multiple doses for a few days. Intravenous ⁵¹Cr(5 μCi/kg in 1 ml/kg PBS) is administered 1 hr after the lastdrug/vehicle dose, and feces collected for 24 hr in a metabolism cageand assessed for excreted ⁵¹Cr by gamma-counting. ⁵¹Cr fecal excretionis calculated as a percent of total injected dose.

Rat Aortic Smooth Muscle Rings in Male Spargue-Dawley Rats

Preparation of Rat Aortic Smooth Muscle Rings Male Sprague-Dawley Rats(Charles River Laboratories (Wilmington, Mass.) are euthanized byintraperiton injection of a high dose of sodium pentobarbitone (80-100mg/kg). The thoracic aorta is rapidly excised and immediately placed ina Petri dish containing warm (37° C.) oxygenated (95% 0, and 5% C02)Kreb's buffer (composition per millimolar: NaCl (119); KCl (4.69);CaCl₂·H₂O (2.52); MgSO₄·7H₂O (0.57); NaHCO₂, (25); NaH2PO, H₂O (1.01)and glucose (11.1). Under a stereoscopic dissecting microscope, theaorta is cleaned, freed from adhering fat and connective tissues. Thetissue is cut into ring segments, each approximately 2-3 mm in length.

For experiments to measure relaxation of the tissue under variousconditions, a stainless steel tissue holder and an U-shaped stainlesssteel wire are inserted into the lumen of the aortic ring. The tissueholder anchored the ring at the bottom of the organ bath whereas the endof the U-shaped steel wire is tied with fine silk thread so that itconnected to the Fr-202 transducer. The tissue holder and the steel wirealong with the aortic ring are then suspended in a 5-ml, double-jacketedtemperature-controlled glass organ bath (Radnoti Glass Technology, Inc.,Monrovia, Calif.) filled with fresh Kreb's buffer. A mixture of 95% O₂and 5% CO₂ is bubbled through a porous sintered disc at the bottom ofthe bath. The rings are given an initial resting tension of 1.5 g andthe preparation is allowed to equilibrate at the initial tension forabout 90 minutes. During this equilibration period, the bath fluid ischanged every 15 minutes and replaced with fresh prewarmed (37° C.)Kreb's buffer. The isometric tension of the aortic muscle at rest andits response to different stimuli are recorded on a Power Macintosh 6100computer via a MacLab 8/S computer interface (CB Sciences, Inc, Milford,Mass.) after an initial amplification through a low-noise EM-400bioamplifier (CB Sciences, Inc, Milford, Mass.). Contractileresponsiveness of the tissue strips is established with 10 TMphenylephrine, and the strips are incubated with the drug for 20 minutesto establish a steady level of contraction.

To test the relaxation effects, test compounds can be added to thephenylephrine precontracted strips in the tissue bath at cumulativeconcentrations of 0.1 μM to 0.1 mM. Concentration of test compounds maybe increased only after relaxation at the previous concentration hadreached a plateau level.

Gastric Erosion Model in Rats

The gastric protective effects of the combination of the presentinvention co-administered with aspirin may be evaluated in the followingassay.

Male Wistar rats (200-250 g) were fasted for 16-18 h prior to use forexperiment. Aspirin, rofecoxib in combination with aspirin (dosedseparately), or test compound in combination with aspirin (dosedseparately) were given on the morning of the experiment at a dosingvolume of 1 ml/kg in 0.5% methocel. Three hr later, the animals wereeuthanized by CO₂ inhalation and the stomach removed, rinsed in salineand prepared for imaging processing. Microscopic pictures of the stomachwere taken using a digital camera and gastric erosions were measuredusing an imaging software by an observer unaware of the treatmentgroups. The length of gastric erosions was measured in mm and the totallength of all erosions from each stomach was obtained and used asgastric damage score.

This model is also described in S. Fiorucci, et al., Gastroenterology,vol. 123, pp. 1598-1606, 2002 and M. Souza, et al., Am. J. Physiol.Gastrointest. Liver Physiol., vol. 285, pp. G54-G61, 2003.

REPRESENTATIVE EXAMPLES

The invention will now be illustrated by the following non-limitingexamples in which, unless stated otherwise:

all operations were carried out at room or ambient temperature, that is,at a temperature in the range 18-25° C.; evaporation of solvent wascarried out using a rotary evaporator under reduced pressure (6004000pascals: 4.5-30 mm. Hg) with a bath temperature of up to 60° C.; thecourse of reactions was followed by thin layer chromatography (TLC) andreaction times are given for illustration only; melting points areuncorrected and ‘d’ indicates decomposition; the melting points givenare those obtained for the materials prepared as described; polymorphismmay result in isolation of materials with different melting points insome preparations; the structure and purity of all final products wereassured by at least one of the following techniques: TLC, massspectrometry, nuclear magnetic resonance (NMR) spectrometry ormicroanalytical data; yields are given for illustration only; whengiven, NMR data is in the form of delta (δ) values for major diagnosticprotons, given in parts per million (ppm) relative to tetramethylsilane(TMS) as internal standard, determined at 300 MHz, 400 or 500 MHz usingthe indicated solvent; conventional abbreviations used for signal shapeare: s. singlet; d. doublet; t. triplet; m. multiplet; br. broad; etc.:in addition “Ar” signifies an aromatic signal; chemical symbols havetheir usual meanings; the following abbreviations have also been used v(volume), w (weight), b.p. (boiling point), m.p. (melting point), L(liter(s)), mL (milliliters), g (gram(s)), mg (milligrams(s)), mol(moles), inmol (millimoles), eq (equivalent(s)).

The following abbreviations have the indicated meanings:

-   -   Ac=acetyl    -   Boc-Glycine=N-tert-butoxycarbonyl-glycine    -   DIBAL=diisobutylaluminum hydride    -   DMAP=4-(dimethylamino)pyridine    -   DMF=N,N-dimethylformamide    -   EDCl=1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride    -   HF.pyr=hydrogen fluoride pyridine (70/30)    -   TBS=tert-butyl(dimethyl)silyl    -   TBSCl=tert-butyl(dimethyl)silyl chloride    -   THF=tetrahydrofuran

Alkyl Group Abbreviations

Me=methyl

Et=ethyl

t-Bu=tertiary butyl

The Dess-Martin reagent, having the following structure, is known in theart.

See Dess, D. B.; Martin, J. C., J. Org. Soc., 1983, 48, 4155.

Example 1 5,6-bis(nitrooxy)hexyl(2Z)-4-(acetyloxy)-3-[4-(methylsulfonyl)phenyl]-2-phenylbut-2-enoate

Step 1: (2Z)-2-[4-(methylsulfonyl)phenyl]-3-phenylbut-2-ene-1,4-diol

To a solution of 110 g of4-(4-methanesulfonyl-phenyl)-3-phenyl-5H-furan-2-one in 1.5 L ofdichloromethane stirred at −78° C., 150 mL of DIBAL was added dropwise.The resulting mixture was warmed to room temperature and stirredovernight. The reaction mixture was then cooled to −78° C., and 1.2 L of1 M aqueous NaOH was added dropwise. After the addition, the resultingmixture was warmed to room temperature and the organic phase wasseparated. The aqueous phase was extracted with dichloromethane. Theorganic phases were combined and dried over Na₂SO₄. 110 g of the titledcompound was obtained after evaporation. ¹H NMR (acetone-d6, 500 MHz): δ7.69 (d, 2H), 7.36 (d, 2H), 7.16-7.05 (m, 5H), 4.66 (d, 2H), 4.63 (d,2H), 4.19 (t, 1H, OH), 4.17 (t, 1H, OH), 3.04 (s, 3H).

Step 2:(2Z)₄-{[tert-butyl(dimethyl)silyl]oxy}-2-[4-(methylsulfonyl)phenyl]-3-phenylbut-2-en-1-ol

To a solution of 110 g of(2Z)-2-[4-(methylsulfonyl)phenyl]-3-phenylbut-2-ene-1,4-diol and 50 g ofimidazole in 1 L of THF stirred at −78° C., a solution 51 g of TBSCl in250 mL of dichloromethane was added dropwise. The resulting mixture wasstirred at −78° C. for 30 min. Brine was then added and warmed to roomtemperature. The organic phase was separated and the aqueous phase wasextracted with EtOAc. The organic phases were combined and dried overNa₂SO₄ and evaporated. The resulting crude material was purified byflash chromatography to afford 25.6 g of the title compound as a whitesolid. ¹H NMR (acetone-d6, 500 MHz): a 7.69 (d, 2H), 7.37 (d, 2H),7.18-7.04 (m, 5M), 4.77 (s, 2H), 4.65 (d, 2H), 3.96 (t, 1H, OH), 3.03(s, 3H), 0.84 (s, 9H), 0.01 (s, 6H).

Step 3:(2Z)-4-{[tert-butyl(dimethyl)silyl]oxy}-2-[4-(methylsulfonyl)phenyl]-3-phenylbut-2-enylacetate

To a solution of 46 g of(2Z)-4{[tert-butyl(dimethyl)silyl]oxy}-2-[4-(methylsulfonyl)phenyl]-3-phenylbut-2-en-1-olwith 120 mmol of DMAP in 1 L of dichloromethane, 120 mmol of aceticanhydride was added dropwise. The resulted mixture was stirred at rt for1 h. The reaction mixture was loaded on a silica gel column and elutedwith EtOAc to afford 50.5 g of the titled compound as a white solid. ¹HNMR (acetone-d6, 500 MHz): δ 7.68 (d, 2H), 7.33 (d, 2H), 7.15-7.04 (m,5H), 5.16 (s, 2H), 4.75 (s, 2H), 3.02 (s, 3H), 1.92 (s, 3H), 0.81 (s,9H), −0.03 (s, 6H).

Step 4: (2Z)-4-hydroxy-2-[4-(methylsulfonyl)phenyl]-3-phenylbut-2-enylacetate

To a solution of 50.5 g of(2Z)-4-{[tert-butyl(dimethyl)silyl]oxy}-2-[4-(methylsulfonyl)phenyl]-3-phenylbut-2-enylacetate in 125 mL of MeCN, 10 mL of PyHF was added and the resultedmixture was stirred at rt for 1.5 h. The reaction mixture was dilutedwith 600 mL of toluene and then loaded on silica gel column and elutedwith EtOAc. The solvent was evaporated to afford 38.3 g of the titledcompound. ¹H NMR (acetone-d6, 500 MHz): δ 7.68 (d, 2H), 7.32 (d, 2H),7.15-7.00 (m, 5H), 5.20 (s, 2H), 4.62 (d, 2H), 4.09 (t, 1H, OH), 3.02(s, 3H), 1.92 (s, 3H).

Step 5:(2Z)-4-(acetyloxy)-3-[4-(methylsulfonyl)phenyl]-2-phenylbut-2-enoic acid

To a solution of 38.3 g of(2Z)-4-hydroxy-2-[4-(methylsulfonyl)phenyl]-3-phenylbut-2-enyl acetatein 500 mL of dichloromethane, 47 g of Dess-Martin reagent was added andthe resulted mixture was stirred at rt for 2 h. Then 2 mL of water wasadded and the resulted mixture was stirred at rt for 1 h. Then themixture was filtered and evaporated. The crude thus obtained wasdissolved in a solvent mixture of 200 mL of THF with 200 mL of t-BuOH.To the resulted mixture, 30 mL of 2-methyl-2-butene was added andfollowed by the addition of 200 mL of 1.2 M of phosphoric acid and 200mL of 1 M of NaClO₂. The resulting mixture was stirred at rt for 30 nmin. The organic phase was separated and the aqueous phase was extractedwith EtOAc. The organic phase was combined, dried over Na₂SO₄, filtered,and then evaporated. The crude was purified by recrystallization fromether to afford 37 g of the titled compound as white solids ¹H NMR(acetone-d6, 500 MHz): δ 7.76 (d, 2H), 7.43 (d, 2H), 7.18-7.12 (m, 3H),7.12-7.08 (m, 2H), 5.24 (s, 2H), 3.05 (s, 3H), 1.88 (s, 3H).

Step 6: 5,6-dibromohexyl acetate

To a solution of hex-5-en-1-ol (30.9 g, 309 mmol) and DMAP (41.5 g, 340mmol, 1.1 equiv) in CH₂Cl₂ (750 mL, 0.4 M) at −78° C., was added aceticanhydride (32.1 mL, 340 mmol, 1.1 equiv). The reaction was stiffed at rtfor 1 h. The product was passed through a plug of silica gel using 20%EA/Hex to afford the desired product (42.7 g, Yield=97%) as a colorlessoil. The compound was used directly for bromination. To a solution ofhex-5-en-1yl acetate (42.7 g, 300 mmol) in CH₂Cl₂ (600 mL, 0.5 M) at−78° C., was added bromine (330 mL, 330 mmol, 1.1 equiv). The reactionwas stirred at −78° C. for 15 min then warmed to rt. The solvent wasevaporated to afford the desired product (89 g, Yield 98%) as ayellowish oil. ¹H NMR (500 MHz, acetone-d6): δ 4.38-4.32 (m, 1H), 4.04(t, 2H), 3.95-3.93 (m, 1H), 3.84-3.80 (m, 1H), 2.16-2.10 (m, 1H), 1.98(s, 3H), 1.90-1.82 (m, 1H), 1.72-1.62 (m, 3H), 1.56-1.48 (m, 1H).

Step 7: 5,6-bis(nitrooxy)hexyl acetate

To a solution of 5,6-dibromohexyl acetate (89 g, 295 mmol) in CH₃CN (600mL, 0.282 M) at rt was added silver nitrate (200 g, 1180 mmol, 4 equiv).The reaction was stirred at 80° C. overnight then evaporated to dryness.The residue was suspended in EtOAc, sonicated and filtered through aplug of silica gel and washed with EA. The product was purified bycombi-flash 3×120 g silica gel cartridge using gradient (0-5% in 5 min,5-55% in 30 min, 55-70% EA/Hex in 10 min) to afford the desired product(65.2 g, Yield=83%) as a yellowish oil. ¹H NMR (500 MHz, acetone-d6): δ5.52-5.46 (m, 1H), 5.00 (dd, 1H), 4.72 (dd, 1H), 4.05-4.03 (m, 2H), 1.96(s, 3H), 1.88-1.84 (m, 2H), 1.71-1.65 (m, 2H), 1.60-1.50 (m, 2H).

Step 8: 6-hydroxyhexane-1,2-diyl dinitrate

To a solution of 5,6-bis(nitrooxy)hexyl acetate (31.3 g, 118 mmol) inTHF-EtOH (1:1, 0.492 M) at 0° C., was added a solution of sodiumhydroxide (2 N, 126 mL, 251 mmol, 2.1 equiv) dropwise over 5 min. Thereaction was stirred at rt for 2 h. The reaction mixture was quenchedwith a saturated NaHCO₃ solution and extracted 3 times with EA. Thecombined organic layers were washed with brine, dried over Na₂SO₄,filtered and evaporated. The product was purified by combi-flash 2×120 gsilica gel cartridge using gradient (0-5% in 5 min, 5-55% in 30 min,55-70% BA/Hex in 10 min) to afford the desired product (24.5 g,Yield=92%) as a pale yellowish oil. ¹H NMR (500 MHz, acetone-d6): δ5.53-5.47 (m, 1H), 5.00 (dd, 1H), 4.72 (dd, 1H), 3.55 (d, 2H), 3.50 (t,1H), 1.88-1.80 (m, 2H), 1.58-1.51 (m, 4H).

Step 9: 5,6-bis(nitrooxy)hexyl(2Z)-4-(acetyloxy)-3-[4-(methylsulfonyl)phenyl]-2-phenylbut-2-enoate

A solution of 2.5 g of(2Z)-4-(acetyloxy)-3-[4-(methylsulfonyl)phenyl]-2-phenylbut-2-enoicacid, 10 mmol of 5,6-bis(nitrooxy)hexan-1-ol, 15 mmol of DMAP and 10mmol of EDCI was stirred at rt for 3 h. Then, AcOH (2-mL) was added andthe mixture was filtered through a pad of silica gel and washed withEtOAc, evaporated, purified by flash chromatography (15-50%EtOAc/hexane) to afford 2.45 g of the desired compound as a white solid.¹H NMR (acetone-d6, 500 MHz): δ 7.79 (d, 2H), 7.45 (d, 2H), 7.21-7.16(m, 1H), 7.13-7.08 (m, 2H), 5.52-5.44 (m, 1H), 5.21 (s, 1H), 4.98 (dd,1H), 4.72 (dd, 1H), 4.29 (t, 2H), 3.09 (s, 3H), 1.92 (s, 3H), 1.89-1.74(m, 4H), 1.60-1.48 (m 2H).

Example 2 (5R)-5,6-bis(nitrooxy)hexyl(2Z)-4-(acetyloxy)-3-[4-(methylsulfonyl)phenyl]-2-phenylbut-2-enoate

Step 1: hex-5-en-1-yl 4-nitrobenzoate

To a solution of hex-5-en-1-ol (20.0 g, 200 mmol) in CH₂Cl₂ (350 mL,0.57 M) at 0° C. was added triethylamine (33.7 mL, 240 mmol, 1.2 equiv),DMAP (1.22 g, 10 mmol, 0.05 equiv) and then 4-Nitrobenzoyl chloride (39g, 210 mmol, 1.05 equiv.). The reaction was stirred at rt for 2 h. Thereaction mixture was quenched with a saturated NH₄Cl solution andextracted 3 times with CH₂Cl₂. The combined organic layers were washedwith brine, dried over Na₂SO₄, filtered and evaporated. The product waspurified by combi-flash 2×120 g silica gel cartridge using gradient(0-5% in 5 min, 5-25% in 30 min, 25-40% EA/Hex in 10 min) to afford thedesired product (35 g, Yield=70%) as a yellowish oil. ¹H NMR (500 MHz,acetone-d6): δ 8.36 (d, 2H), 8.26 (d, 2H), 5.87-5.79 (m, 1H), 5.03 (d,1H), 4.94 (d, 1H), 4.38 (t, 2H), 2.14 (m, 2H), 1.84-1.78 (m, 2H),1.60-1.54 (m, 2H).

Step 2: (5R)-5,6-dihydroxyhexyl 4-nitrobenzoate

To a solution of AD-mix-beta (34 g) in t-BuOH—H₂O (1:1, 0.077 M) at 0°C., was added hex-5-en-1-yl 4-nitrobenzoate (6 g, 24.07 mmol). Thereaction was stirred at 0° C. overnight. The reaction mixture wasdiluted with 250 mL of EA, quenched by addition of 10 g of sodiummetabisulfite and stirred 30 min at 0° C. The mixture was allowed tostir at rt for 1 h then was extracted 3 times with EtOAc, washed withbrine, dried over Na₂SO₄, filtered and evaporated. The compound wasrecrystallized with ether and stirred in the cold room overnight fortwice to afford 3.3 g of the titled compound as a white solid (greaterthan 99% in e.e. by Mosher derivatives analysis). ¹H NMR (500 MHz,acetone-d6): δ 8.36 (d, 2H), 8.27 (d, 2H), 4.38 (t, 2H), 3.62-3.54 (m,3H), 3.49-3.45 (m, 1H), 3.41-3.35 (m, 1H), 1.87-1.77 (m, 2H), 1.69-1.62(m, 1H), 1.59-1.49 (m, 2H), 1.46-1.40 (m, 1H).

Step 3: (5R)-5,6-bis(nitrooxy)hexyl 4-nitrobenzoate

To a solution of nitric acid (8 mL, 178 mmol, 15.75 equiv) in CH₂Cl₂ (20mL, 0.565 M) at −78° C., was added sulfuric acid (2 mL, 37.5 mmol, 3.32equiv) and then a solution of (5R)-5,6-dihydroxyhexyl nitrobenzoate (2.5g, 8.83 mmol) in CH₂Cl₂ (10 mL). The reaction was stirred at 0° C. for 2h. The reaction mixture was poured on ice (ca 200 g) and extracted 3times with CH₂Cl₂. The combined organic layers were washed with water,brine, dried over Na₂SO₄, filtered and evaporated. The product waspurified by combi-flash 120 g silica gel cartridge using gradient (0-5%in 5 nm in, 5-40% in 25 min, 40-70% EA/Hex in 10 nm in) to afford thedesired product (3.1 g, Yield=91%) as a viscous yellowish oil. ¹H NMR(500 MHz, acetone-d6): δ 8.35. (d, 2H), 8.26 (d, 2H), 5.56-5.52 (m, 1H),5.03 (dd, 1H), 4.75 (dd, 1H), 4.41 (t, 2H), 1.98-1.88 (m, 4H), 1.76-1.66(m, 2H).

Step 4: (2R)-6-hydroxyhexane-1,2-diyl dinitrate

To a solution of (5R)-5,6-bis(nitrooxy)hexyl 4-nitrobenzoate (3.1 g, 8.3mmol) in THF-EtOH (1:1, 0.5 M) at 0° C. was added sodium hydroxide 2N(10 mL, 20 mmol, 2 equiv) dropwise over 5 min. The reaction was stirredat rt for 2 h. The reaction mixture was quenched with a saturated NaHCO₃solution and extracted 3 times with EtOAc. The combined organic layerswere washed with brine, dried over Na₂SO₄, filtered and evaporated. Theproduct was purified by combi-flash 120 g silica gel cartridge usinggradient (0-5% in 5 min, 5-55% in 30 min, 55-70% EA/Hex in 10 min) toafford the desired product (1.51 g, Yield=81%) as a colorless oil. ¹HNMR (500 MHz, acetone-d6): δ 5.52-5.48 (m, 1H), 5.01 (dd, 1H), 4.72 (dd,1H), 3.56-3.50 (m, 3H), 1.88-1.81 (m, 2H), 1.54-1.50 (m, 4H).

Step 5: (5R)-5,6-bis(nitrooxy)hexyl(2Z)-4-(acetyloxy)-3-[4-(methylsulfonyl)phenyl]-2-phenylbut-2-enoate

A solution of 3 g of(2Z)-4-(acetyloxy)-3-[4-(methylsulfonyl)phenyl]-2-phenylbut-2-enoicacid, 1.7 g of (2R)-6-hydroxyhexane-1,2-diyl dinitrate, 10 mmol of DMAPand 10 mmol of EDCI was stirred in 40 mL of dichloromethane at rt for 2h. Then, acetic anhydride (0.5 mL) was added and the mixture wasfiltered through a pad of silica gel and washed with EtOAc, evaporated,purified by flash chromatography (15-50% EtOAc/hexane) to afford 2.8 gof the desired compound as a white solid. ¹H NMR (acetone-d6, 500 MHz):δ 7.79 (d, 2H), 7.45 (d, 2H), 7.21-7.16 (m, 1H), 7.13-7.08 (m, 2H),5.52-5.44 (m, 1H), 5.21 (s, 1H), 4.98 (dd, 1H), 4.72 (dd, 1H), 4.29 (t,2H), 3.09 (s, 3H), 1.92 (s, 3H), 1.89-1.74 (m, 4H), 1.60-1.48 (m 2H).

Example 3 4,5-bis(nitrooxy)pentyl(2Z)-4-(acetyloxy)-3-[4-(methylsulfonyl)phenyl]-2-phenylbut-2-enoate

Step 1: 4,5-bis(nitrooxy)pentyl alcohol

To a solution of 18.7 g of 4,5-bis(nitrooxy)pentyl acetate in 150 mL ofEtOH at 25° C. was added 2.96 g of NaOH. The mixture was stirred for 90min, quenched by addition of NaHCO₃ sat., extracted with EtOAc, washedwith brine and dried over sodium sulfate. Purification by flashchromatography afforded 6.3 g of the desired compound as an orange oil.¹H NMR (acetone-d6, 500 MHz): δ 5.56 (m, 1H), 5.01 (dd, 1H), 4.73 (dd,1H), 3.68 (t, 1H), 3.60 (m, 2H), 1.93-1.86 (m, 2H), 1.69-1.64 (m, 2H).

Step 2: 4,5-bis(nitrooxy)pentyl(2Z)-4(acetyloxy)-3-[4-(methylsulfonyl)phenyl]-2-phenylbut-2-enoate

To a solution of 1.72 g of(2Z)-4-(acetyloxy)-3-[4-(methylsulfonyl)phenyl]-2-phenylbut-2-enoic acidin 20 mL of CH₂Cl₂ at 0° C. was added 1.06 g of 4,5-bis(nitrooxy)pentylalcohol, 225 mg of DMAP and 970 mg of EDCI. The mixture was stirred atRT for 2 h then quenched by addition of NH₄Cl sat., extracted withEtOAc, washed with NaHCO₃ sat., brine and dried over sodium sulfate.Purification by flash chromatography afforded 1 g of the titled compoundas a white solid. ¹H NMR (acetone-d6, 500 MHz): δ 7.77 (d, 2H), 7.43 (d,2H), 7.18-7.16 (m, 3H), 7.08 (dd, 2H), 5.53-5.50 (m, 1H), 5.20 (s, 1H),4.97 (dd, 1H), 4.69 (dd, 1H), 4.31 (m, 2H), 3.05 (s, 2H), 1.89 (m, 7H).

Example 4 3,4-bis(nitrooxy)butyl (2Z(acetyloxy)-3-[(methylsulfonyl)phenyl]-2-phenylbut-2-enoate

Step 1: 3,4-bis(nitrooxy)butyl alcohol

To a solution of 27.8 g of butan-1,2,4-triol in 150 mL of acetone wasadded 27.3 mL of 2,2-dimethoxypropane and 10 mg of PTSA at RT. Thereaction was stirred for 3 h then quenched by addition of 200 mg ofNaHCO₃. After stirring for 15 min, the solvent was evaporated. The crudecompound was filtered through a pad of silica gel using 60%EtOAc/hexanes to afford 30 g of the desired compound as a colorless oil.The compound was used directly in the next step. To a solution of 20 gof 2-(2,2-dimethyl-1,3-dioxolan-4-yl)ethanol in 200 mL of CH₂Cl₂ at 0°C. were added 33.5 g of DMAP and 26 mL of acetic anhydride. The mixturewas stirred 2 h at RT then quenched by filtration through a short pad ofsilica gel. Purification by flash chromatography afforded 20.7 g of thedesired compound as a colorless oil. The compound was used directly forthe next step. Sulfuric acid (40 mL) was added to nitric acid (20 mL) at−78° C. and then stirred at 0° C. for 10 min. At −78° C., a solution of10 g of 2-(2,2-dimethyl-1,3-dioxolan-4-yl)ethyl acetate in 20 mL ofCH₂Cl₂ was added and the reaction was stirred for 1 h. Quenching wasdone by adding the reaction mixture to 500 g of ice in an 1 L erlenmeyerflask. The compound was then extracted with CH₂Cl₂, washed with NaHCO₃,brine and dried over sodium sulfate. The crude compound was useddirectly for the next step without further purification. To a solutionof 5.1 g of 3,4-bis(nitrooxy)butyl acetate in 40 mL of EtOH at 25° C.was added 855 mg of NaOH. The mixture was stirred for 1 h, quenched byaddition of NaHCO₃ sat., extracted with EtOAc, washed with brine anddried over sodium sulfate. Purification by flash chromatography afforded1 g of the desired compound as a yellowish oil. ¹H NMR (acetone-d6, 500MHz): δ 5.71-5.66 (m, 1H), 5.07 (dd, 1H), 4.76 (dd, 1H), 3.97 (t, 1H),3.77-3.68 (m, 2H), 2.02-1.95 (m, 2H).

Step 2: 3,4-bis(nitrooxy)butyl (2Z)4(acetyloxy)-3-[4-(methylsulfonyl)phenyl]-2-phenylbut-2-enoate

To a solution of 1.72 g of(2Z)-4-(acetyloxy)-3-[4-(methylsulfonyl)phenyl]-2-phenylbut-2-enoic acidin 30 mL of CH₂Cl₂ at 0° C. was added 750 mg of 3,4-bis(nitrooxy)butylalcohol, 560 mg of DMAP and 880 mg of EDCI. The mixture was stirred atRT for 2 h then quenched by addition of NH₄Cl sat., extracted withEtOAc, washed with NaHCO₃ sat., brine and dried over sodium sulfate.Purification by flash chromatography afforded 930 mg of the titledcompound as a white solid. ¹H NMR (acetone-d6, 500 MHz): δ 7.77 (d, 2H),7.43 (d, 2H), 7.17-7.15 (m, 3H), 7.08 (dd, 2H), 5.56-5.52 (m, 1H), 5.22(s, 2H), 4.95 (dd, 1H), 4.69 (dd, 1H), 4.47-4.41 (m, 2H), 3.05 (s, 3H),2.32-2.19 (m, 2H), 1.89 (s, 3H).

1. A compound of Formula I

or a pharmaceutically acceptable salt thereof, wherein: n is an integerfrom 1 to 6; R¹ is selected from the group consisting of: (a) S(O)₂CH₃and (b) S(O)₂NH₂, R² and R³ each are independently selected from thegroup consisting of: (a) hydrogen, (b) halo, (c) C₁₋₆alkoxy, (d)C₁₋₆alkylthio, (e) CN, (f) CF₃, (g) C₁₋₆alkyl, and (h) N₃; R⁴ isselected from the group consisting of (a) C₁₋₄alkyl, optionallysubstituted with 1 to 3 halo groups, (b) phenyl, naphthyl or a 5- or6-membered aromatice heterocycle, each optionally substituted with 1 to3 halo groups, (c) —O—R⁵, and (b) —(CH₂)_(m)—N(R⁶)(R⁷); m is an integerfrom 1 to 4; and R⁵, R⁶ and R⁷ are each independently selected from thegroup consisting of hydrogen and C₁₋₄alkyl, optionally substituted with1 to 3 halo groups.
 2. The compound according to claim 1 wherein R¹ isS(O)₂CH₃, and R² and R³ are both hydrogen.
 3. The compound according toclaim 1 wherein n is 1, 2 or
 3. 4. The compound according to claim 1wherein R⁴ is C₁₋₄alkyl.
 5. The compound according to claim 4 wherein R⁴is methyl.
 6. A method of treating an inflammatory disease susceptibleto treatment with a non-steroidal anti-inflammatory agent comprisingadministering to a patient in need of such treatment of a non-toxictherapeutically effective amount of a compound according to claim
 1. 7.The method according to claim 6 wherein the patient is also at risk of athrombotic cardiovascular event and the patient is on aspirin therapy toreduce the risk of the cardiovascular event.
 8. A method of treatingcyclooxygenase mediated diseases advantageously treated by an activeagent that selectively inhibits COX-2 in preference to COX-1 comprisingadministering to a patient in need of such treatment of a non-toxictherapeutically effective amount of a compound according to claim
 1. 9.The method according to claim 8 wherein the patient is also at risk of athrombotic cardiovascular event and the patient is on aspirin therapy toreduce the risk of the cardiovascular event.
 10. A method for treating achronic cyclooxygenase-2 mediated disease or condition and reducing therisk of a thrombotic cardiovascular event in a human patient in need ofsuch treatment and at risk of a thrombotic cardiovascular eventcomprising orally concomitantly or sequentially administering to saidpatient a compound according to claim 1 in an amount effective to treatthe cyclooxygenase-2 mediated disease or condition and aspirin in anamount effective to reduce the risk of the thrombotic cardiovascularevent.
 11. The method according to claim 10 wherein the compound isadministered orally on a once daily basis.
 12. The method according toclaim 10 wherein the compound is administered orally on a twice dailybasis.
 13. The method according to claim 10 wherein the cyclooxygenase-2selective mediated disease or condition is selected from the groupconsisting of: osteoarthritis, rheumatoid arthritis and chronic pain.14. The method according to claim 10 wherein aspirin is administered ata dose of about 30 mg to about 1 g.
 15. The method according to claim 14wherein aspirin is administered at a dose of about 80 to about 650 mg.16. The method according to claim 15 wherein aspirin is administered ata dose of about 81 mg or about 325 mg.
 17. The method according to claim10 wherein aspirin is orally administered once daily.
 18. Apharmaceutical composition comprising a compound according to claim 1and aspirin in combination with a pharmaceutically acceptable carrier.19. A pharmaceutical composition comprising a compound according toclaim 1 and a pharmaceutically acceptable carrier.